Electrostatic self-assembled Iridium(III) nano-photosensitizer for selectively disintegrated and mitochondria targeted photodynamic therapy

Photodynamic therapy (PDT) is one of effective cancer therapy methods. It is important to develop a PDT reagent with tumor-targeted ability, high phototoxicity and low dark toxicity. In this study, an iridium(III) complex (Irpy) can electrostatically self-assemble with hyaluronic acid (HA) to form nanostructured Irpy-HA, which exhibited stable spheroid structure and outstanding ability of singlet oxygen (O-1(2)) generation. The photophysical property of Irpy has been well studied, which qualified green light absorption ability and could emit red phosphorescence. The nanostructure and stability of self-assembled Irpy-HA have been well investigated, which can keep its nanostructure at least 30 days. More importantly, Irpy-HA can target to a CD44 receptor in cancer cell membrane for enhancing internalization and selective disintegration. Then, Irpy can accumulate in mitochondria and generate O-1(2) to realize PDT-induced cell apoptosis by green light irradiation. The Irpy-HA could be used as a nanophotosensitizer for effective photodynamic therapy.